Generally, shoelaces are used in most shoes as a means of loosening, tying and fixing the shoes on the feet. However, the shoes with shoelaces have many problems in wearing. For example, when the shoelaces are loosened while moving, they have to be retied, resulting in inconvenience and waste of time. Furthermore, there is also potential danger of wearing shoes with shoelaces. For example, when the shoelaces are accidentally loosened, other people may trip over it, or the shoelaces may be involved in the gap of an escalator, a bicycle chain or a motorcycle pin, which may cause accidents. In addition, wearing the shoes with shoelaces in long term may put excessive pressure on the feet and cause discomfort.
Some shoes use other ways, such as a hook and loop fastener or a sock-type shoe body, as a means of loosening, tying, and fixing the feet. However, the hook and loop fastener has insufficient fixity, and is easily detached. The viscosity of the hook and loop fastener may decrease after using for a long period of time, resulting in inconvenience while moving, and the shoes with the hook and loop fastener are inappropriate for wearing during exercise. The sock-type shoe body also has insufficient strength to fix the feet, and the tightness cannot be adjusted according to the requirements. After using for a long period of time, the sock-type shoe body may be loose, and the requirement of fixing the feet is failed to be achieved.
On the other hand, in general, people can only select shoes in different size according to their foot lengths rather than individual foot shapes. It is a common problem that people purchase the shoes which fail to fit the feet well, as their shoe bodies may be too wide, too narrow, too high, or too flat, and wearing unfit shoes to move may cause discomfort and injury.
In addition, people have gradually paid attention to the concept of energy conservation and carbon reduction. Therefore, how to effectively convert items in daily life into technological green energy products has become a very important topic. In prior arts, the function of autonomous power generation has not been widely used in footwear products. However, with the increasing popularity of the portable electronic products (e.g. smart phones, tablet computers, etc.), it has become a big problem that the batteries of those portable electronic products often run out while the user is in the outdoors, and it is difficult to find a place to charge and it is inconvenient to bring an extra portable charger. Therefore, it is a major issue of the present invention to combine comfortable shoes with a charging function for generating enough electric energy that can be used to charge the portable electronic devices, which are carried by the user who wears the shoes.
Therefore, there is a need of providing an inflatable charging device to solve the drawbacks in prior arts, which can be applied to each of a pair of shoes and serving as a power charger, as well as making the shoe automatically adjustable to be adapted to the personal foot shapes and comfortably wrap and fix the feet.